B.C. Entomological Society. 



grown. On July i8th many of the mines were found to be tenanted 

 by two species of hymenopterous parasites ; one in a small white cocoon 

 some 4 to 5 mm. long, and the other a black pupa 3 mm. in length. The 

 adults of both species hatched out at approximately the same time as 

 the moths. In August their exit-holes were clearly visible on the mined 

 leaf-surface. The species of these have not yet been determined. 



Larva. — Tn the genus Lithocolletis we have an example of " larval 

 dimorphism," the 'genus being divided into two groups, those having a 

 flat larva and those having a cylindrical larva respectively. Miss Braun 

 states that in the entire genus the first three instars are of the flat type, 

 the cylindrical group gaining their typical form with the third moult ; 

 while in the flat group the change to an approach to cylindrical form 

 occurs in the last larval instar preceding the pupa. In the larvse at 

 present collected the two forms are believed to be present, but the 

 subject needs further study before any definite pronouncement can be 

 made. At present, therefore, a short description of the salient features 

 of each form must suffice. 



Flat Larva. — Larvje of the flat type were found ranging from i to 

 7 mm. in length, and the following general description holds good for 

 all : The larva is distinctly depressed. The body tapers towards hind 

 end, this being especially noticeable in the smaller specimens, in which 

 the body tapers very rapidly, assuming a " V-" shape. The head is very 

 much flattened, sub-triangular in shape, two-thirds the breadth of the 

 thorax. In the smaller specimens of the living material examined it was 

 seen to be much retracted into the first thoracic segment. The mouth- 

 parts are clearly visible, being thrust out prominently in front. The 

 presence of dark-brown coloured processes, referred to as " apodemata " 

 by Ivar Tragiirdh, Experimentalfiiltet, Sweden, in his paper " Contri- 

 butions towards the Comparative Morphology of the Trophi of the 

 Lepidopterous Leaf Miners" (Arkiv For Zoologi. Band 8, No. 9, 1913). 

 is well marked, both dorsally and ventrally, in all the larvre examined. 

 The form of these appears to differ in the two forms of larva. Tragiirdh 

 also points out that there is a difference in the genus Lithocolletis in the 

 arrangement of the ocelli of the young and full-grown larva respectively. 

 This has not 3fet been observed in the species. 



The number of segments following the head is thirteen ; the sides of 

 the segments are protuberant, the lateral outline of the body being in 

 consequence strongly crenate. On the dorsal and ventral aspects of the 

 thoracic and abdominal segments, dark patches or " maculae " n^Dpear. 

 These are found to remain constant in shape for corresponding segments 

 in members of the same species in each stage. In the smaller specimens 

 their shape was not so clearly marked. The colour of the living larvae 

 is light green, the maculje being of a brownish colour. The legs of the 

 smaller specimens are very difficult to make out, being merely tubercular 

 projections, surmounted with a circle of hooks. Abdominal legs are 

 present on segments 7, 8, 9, and 13. ^ 



